A touch sensor has been known as an interface for a user to input information to a display device. Installing a touch sensor to a display device allows a user to directly operate an input button or an icon displayed on a screen, facilitating input of information to a display device. For example, Japanese Patent Application Publications No. 2015-18331 and No. 2015-50245 disclose an electronic device having a display device including an organic EL (Electroluminescence) element on which a touch sensor is mounted.